The present disclosure relates to an imaging system, a mount adaptor, an imaging apparatus, and a program.
In recent years, there has been a rapid expansion in the use of digital single-lens reflex cameras, but it has not been possible to respond to the demand for a further reduction in size and weight in camera body size. This is because it is necessary for a single-lens reflex digital camera to accommodate a reflex mirror which switches between an imaging light path and a finder light path and a pentaprism which guides a subject image to a finder (OVF: Optical View Finder) in the camera body.
Therefore, by providing an electronic view finder (EVF) instead of an OVF, a digital single-lens camera (mirrorless digital single-lens camera) referred to as mirrorless, which achieves a reduction in size and weight by removing the reflex mirror, has been introduced. However, the mirrorless digital single-lens camera is not able to perform focus detection in the phase difference detection method using the camera main body due to a sub-mirror which guides the incident light to the focus detection section being removed along with the reflex mirror.
In addition, since the mirrorless digital single-lens camera shortens the flange focal length compared to the digital single-lens reflex camera, an interchangeable lens which was able to be mounted on the digital single-lens reflex camera is not able to be used as it is. Therefore, in order to effectively use the interchangeable lens resources in the related art, the mirrorless digital single-lens camera is made to be able to mount the interchangeable lens used with the digital single-lens reflex camera via a mount adaptor.
Then, in order for it to be possible to mount the interchangeable lens which corresponds to a phase difference detection method, there is a proposal for an imaging apparatus which is provided with a focus detection section of the phase difference detection method in the mount adaptor (for example, International Publication No. 2008/099605).